Telematics units within mobile vehicles provide users with connectivity to a telematics service provider (TSP). The TSP provides users with an array of services ranging from emergency call handling and stolen vehicle recovery to diagnostics monitoring, global positioning system (GPS) aided navigation, map services, and turn-by-turn navigation assistance. In order to provide services to users, the TSP must transmit data to and receive data from a large number of telematics units. Wireless wide area networks (WWANs) provide the infrastructure through which data is transmitted between a TSP's operations control centers (OCCs) and the many telematics units belonging to individual users. In order for a telematics unit to receive data from a TSP OCC and send data to a TSP OCC, the telematics unit must be activated. Activation involves the registration of unique identifiers for the telematics unit with a wireless service provider (WSP). Activation further involves the assignment of network resources to the telematics unit by the WSP. Upon activation, the telematics unit can communicate with a TSP OCC to, e.g., transmit requests to the TSP for provision of services and receive services from the TSP.
The hardware components of a telematics unit that enable connection to the WWAN can be collectively referred to as a network access device (NAD) of the telematics unit. The NAD includes a baseband processor that serves as a mobile termination providing functions that include control of radio transmissions, speech encoding and decoding, error detection and correction, and signaling control. The baseband processor also provides access to a subscriber identity module (SIM) that stores a unique identifier called an international mobile subscriber identity (IMSI). The SIM may be an application contained on a universal integrated circuit card (UICC). A UICC is capable of storing multiple SIM applications and may further store a subscription management module (SMM) serves to control the use of the various SIM applications stored on the UICC. Telematics units additionally include one or more applications processors utilized for providing services to the user as well as for other purposes, e.g. management of the various software components of the telematics unit.